Process of making sulfuric anhydrid.



J. MQFBTRIDGE.

PROCESS OP MAKING SULFURIO ANHYDRID.

APPLIOATION mum NOV. 21. 1908.

988,646. Patented Apr. 4, 1911.

WITNESSES INVENTQR J. MGFETRIDGE- rnoonss or MAKING SULFURIG ANHYDRID.

APPLICATION FILED NOV 21, 1908. 988,646, Patented Apr. 4,1911.

2 SHEETS-SHEET 5.

Fly 2 Fl yiar INVENTOR To all whom itmay concern: I

:rosnrn MoFE'lBIDGE, or vannnaomrr, rnnnsrnvanm.

rnocnss or MAKING su reme mrrmun.

Specification of Letters Patent.

Application filed November 21, 1908. .Serial No. 463.909.

Be it known th'atI, JosnPH'MoFE'mmoE,

a resident of 'Vandergrifhin the county of Westmoreland and State of Pennsylvania,

have invented a new and useful Improvement in Processes of Manufacturing Sulfuric Acid from Sulfid Ores, of which the following is'a specification.

over i to' 1;, inci mes .20

' tervals with This invention relates to a process ofmanufacturing sulfuric anhyrid from iron and co per pyrites, sulfid ores, and'mattes resu ting rom the treatment of such ores.

The object of the invention is to simplify the operation of making sulfuric acid and cheapen the process.

Heretofore the practice has been to crush the ore to eg size lumps and separate the fine portion y sieves. The fine portion of ore will range invsize from fine powder to pea size lumps, and is known to the. trade as fines. The methods now in use are to burn the lam ore in kilns or burners, and the fines in she f burners or mechanical furnaces, and convert the sulfurous anhydrid' resulting from the combustion of the sulfur into sulfuric anhydrid or, hydrated sulfuric acid by the well known contact or chamber process. a

The well known contact process necessitates the use of one or more contact'shafts which are charged and discharged at. in-

and separate; compartments count of their low commercial value, are

. ground to an impalpable powder. This is then fed into a furnace, kiln or shaft, heated to a temperature high enough to ignite the sulfur, preferably being'fed by an air blast or drawn into the furnace by a fan or "blower suction. The pulverulent ore is at once ignited, with formation of sulfurous anhydmd and metallic oxids. The finely divided megyrltes cinders or other forms metallic-contact substance over assin the crushed mass l'tallic oxids are carried along in the furnace with the mixture of sulfurous anhydrid and air, and being in such a fine state of division, act at once as a catalyzer, convertin 30.to 40 per cent. of the sulfurous anhydrid into sul uric anhydrid. and at the same time the gases are urified by the removal of arsenic and the li e by their intimate contact with the fine, non"volatile oxids. The spent metalhc oxids are then separated from the gas.

The resulting sulfuric anhydrid is absorbed 1n strong sulfuric acid in the wellknown absorption towers, and the remaining sulfurous anhydrid converted into sulfuric anhydrid by the continuance of the contact process or into hydrated sulfuric acid by the well known chamber process.

In the accompanying drawings, which illustrate one form of an apparatus-that may be' used in carrying out my invention, Figures 1 and 1 show in parta side elevation' and in part a vertical section, and Fig. 2. a section on the line 22, Fig. 1.'

' The form of apparatus can be varied in construction without departing from the invention. The grinding can be effected by any suitable a paratus. The fine ore is fed into the seale v feed hopper 2 and injected therefrom into furnace 3 by air under ressure admitted through pipe 4. Additional air is admitted in regulated quantities through 0 ening 5. -The furnace 3 is of the rotary cylindrical type and is preheated to such temperature, from 1250 to 1500 degrees Fahrenheit, as to ignite the sulfur in the fine ore. After being once started the burning of the sulfur maintains the heat of the furnace. Whenthe ore strikes the hot zone of furnace 3 the combustion of sulfur is instantaneous, with formation of sulfurous anhydrid, sulfuric anhydrid and metallic oxids.

Ap aratus 6 comprises two parallel rectangu ar chambers, each of which contain a number of superposed horizontal dust collecting shelves 8 and temperature regulating flue 9. At one end is a vertical gas-supply passage 10 controlled by valve 11 and having Patented Ap1u4, 1911.

hoppers 14 and 15.

The sulfuric anhydrid formed in the furnace 3 and dust collector 6, and the unconverted sulfurous anhydrid and air are drawn from dust collector 6 by means vof suction produced by fan '22, through the cast iron pipe 17 to the absorption tower 18 which is packed with acid resisting material 19. The sulfuric anhydrid is absorbed in strong sulfuric acid fed to the tower through pipe 20. The unconverted sulfurous anhydrid and air are drawn from tower 18 through pipe 21 and forced by fan 22 into Glover tower 23 and chamber 24, where the sulfurous anhydrid is converted into hydrated sulfuric acid a :-by oxidation and hydration by the well known chamber process.

During the passage of the mixture of sulfur ases, air and metallic oxids through the rnace and dust collector, in which a temperature of from 1250 to 1500 degrees Fahrenheit is maintained, 30,to per cent.

of sulfuricanhydrid is formed, and arsenic and the like removed.

The catalytic action takes place simultaneously with the burning of the ore in the furnace proper and in the dust collector instead of in a separate contact shaft as heretofore.

What I claim is: i

1. The rocess of manufacturing sulfuric, anhydrid rom metallic sulfids, consisting in reducing said sulfids to a pulverulent condition, then injecting the same in a thin stream together with a regulated volume of air into a furnace heated to a temperature high enough to at once ignite the sulfur and convert it into sulfurous anhydrid, and carrying the gases so produced along with the fine metallic oxids soproduced and air, and by contact with said oxids converting the sulfurous anhydrid into sulfuric anhydrid.

2. The process of manufacturing sulfuric anhydrid from metallic sulfids, consisting in reducing said sulfids to ar-fine powder, then injecting the same by means of an air blast of regulated volume into a furnace heated to a temperature high enough to at once ignite the sulfur, decomposing the sulfur bearing material, forming sulfurous anhydrid and metallic oxids, and carrying the gases so produced in contact with the fine oxids so produced and air, whereby catalytic action converts sul'furous anhydrid into sulfuric anhydrid. 4

3. The process of manufacturing sulfuric anhydridfrom metallic sulfids, consisting in reducing said sulfids to a fine powder, then projecting the same by means of a blast and suction into a furnace heated to a temperature high enough to at once ignite the sulfur, I

decomposing the sulfur bearing material forming sulfurous anhydrid and metallic oxids, and carrying the gases so producedjin contact with the fine metallic oxids so produced, thereby purifying the gases by freeing them from'arsenic and the like, and by the catalytic action of said oxids converting the sulfurous anhydrid into sulfuric anhyr drid. P y

In testimony whereof, I have hereunto set my hand.

v JOSEPH MOFETRIDGE;

Witnesses:

R. G. Scorr, Jr.-, W. L. DAVIS. 

